This chamber did come with a vacuum gauge, but it only goes down to 10E-3 torr, so it’s not suitable for our needs.
What we need is an Ionization gauge. I found one product that I really liked, the Intru Tech Hornet. It seems very easy to use: install conflat, plug in power, and get a reading. Coming in at under $1K, this gauge is in my budget.
However, this is the scenario I imagine happening if I get this gauge: we get the pressure down to 10E-6 torr and that’s as low as it goes. At this point you need a Residual gas analyzer, to make any further diagnosis. If you see air, you have a real leak from the outside. If you see water you need a bake-out. If you see hydrocarbons, you have outgassing. I found the extorr, which combines a Pirani, Ion Gauge, and RGA. It’s $3,450, and a stretch for my budget, but would be the only gauge you needed. It requires a windows box, and the software looks clunky.
Would an RSA also be useful for monitoring the pressure of the process gasses (deuterium/hydrogen/boron/helium)?
Prometheus Fusion Perfection 
Tom Ligon says an RGA is nearly essential.
There is a company that makes an all metal bare ionization gauge. I’ll see if I can find a link.
Here are some links:
http://www.televac.com/ranges_sensors/eti_8140.html
http://www.televac.com/ranges_sensors/BAS_ion.html
http://www.televac.com/ranges_sensors/eti_8130.html
Here is another:
http://www.helixtechnology.com/products/category54.html
Also there is a company that makes an RGA “kit”. I haven’t found the link yet.
Here is an interesting RGA company:
http://www.hidenanalytical.com/
For all your residual gas analysis needs
Hydrogen, Deuterium and Tritium Analyses:
http://www.hidenanalytical.com/index.php/en/applications/103-gas-analysis
anyone know what software this requires?
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=310114003615&_trksid=p3907.m32&_trkparms=tab%3DWatching#ht_2755wt_1140